]Sro. 10. — Tlie Rattle of the Rattlesnake. By Samuel Garman. The habit of sloughing is common to all the serpents. A short time before the removal takes place, the new epiderm makes its appearance beneath the old. Its presence is easily detected by a whitish color under the outer layer. The milky tint of the second layer extends over the whole body ; on the eyeball it interferes greatly with the sight. During the time of its formation, several weeks, while the vision is affected, the snake prefers seclusion, and is disinclined to partake of food. Some days before casting, about a week in the most recent case followed, the milkiness vanishes, the skin resumes its ordinary aspect, and the sight becomes again as keen as formerly. By rubbing the lips the slough is loosened around the mouth, then it is pushed over the head to the neck, whence it is taken back over the body. From the neck backward it is, in some cases, removed by means of a coil or two of the tail, the body being crowded through and the epiderm left behind. A hole in the ground or between rocks, the sticks in a brush heap or the stalks in the grass, answer the same purpose as the ring made by the tail. Some manage to get the coat back until under the ventral scales, when the latter are used somewhat as in gliding, their free hinder edges catching and stripping off the slough as the body is moved slowly forward. From the hinder part of the body the removal is an easier matter : the loosened portion is caught around a stick or under a stone, and with a pull the balance is taken off in an instant. The slough comes away like damp paper; it is wet with a sticky mucus on the inner side, turned outward in the operation. The mode of growth and of removal is similar among the rattlesnakes. These snakes differ in retaining a portion of each slough, that covering the tip of the tail, to form one of the rings of the rattle. The attachment is purely me-chanical ; the rings are merely the sloughs of the end of the tail. On the majority of the snakes, both the venomous and the non-venomous, the tail tapers more or less gradually to a point. At the end it is protected by a sub-conical cap of the epiderm. Under the latter lies the skin, and under it again the termination of the vertebral column, — a bone formed of vertebrae that have coalesced and changed VOL. XIII. — NO. 10.